People suffering from various forms of diabetes routinely need to test their blood to determine the level of blood glucose. The results of such tests can be used to determine what, if any, insulin or other medication needs to be administered. In one type of blood glucose testing system, sensors are used to test a sample of blood.
Such a sensor may have a generally flat, rectangular shape with a front or testing end and a rear or contact end. The sensor contains biosensing or reagent material that will react with blood glucose. The testing end of the sensor is adapted to be placed into the fluid being tested, for example, blood that has accumulated on a person's finger after the finger has been pricked. The fluid is drawn into a capillary channel that extends in the sensor from the testing end to the reagent material by capillary action so that a sufficient amount of fluid to be tested is drawn into the sensor. The fluid then chemically reacts with the reagent material in the sensor with the result that an electrical signal indicative of the blood glucose level in the blood being tested is supplied to contact areas located near the rear or contact end of the sensor.
To couple the electrical signals produced at the sensor contacts to monitoring equipment, the sensors need to be inserted into sensor holders prior to the sensor end being placed into the fluid being tested. The sensor holders have corresponding mating contact areas that become coupled to the contacts on the sensor when the sensor is inserted into the holder. Consequently, the holders act as an interface between the sensor and monitoring equipment that accumulates and/or analyzes the test results.
Prior to being used, the sensors typically need to be maintained at an appropriate humidity level so as to insure the integrity of the reagent materials in the sensor. Sensors can be packaged individually in tear-away packages so that they can be maintained at the proper humidity level. For instance, blister-type packaging methods could be used. In this connection, the packages can include desiccant material to maintain the proper humidity in the package. To use an individual sensor for testing blood glucose, the package must be opened by tearing the seal. Alternatively, some packages require the user to exert force against one side of the package resulting in the sensor bursting or rupturing the foil on the other side. As can be appreciated, the opening of these packages can be difficult. Moreover, once the package is opened, the user needs to be sure that the sensor is not damaged or contaminated as it is being placed into the sensor holder and used to test the blood sample.
Some users have experienced difficulties in the operation and/or manipulation of the prior art sensor instruments. For example, users with limited dexterity may find it difficult to remove a used sensor from the device. Because the used sensor contains blood or other fluids, the sensor should be disposed of immediately after the testing procedure is completed. Moreover, physical handling of the used sensor should be avoided to prevent or inhibit the spreading of blood-born diseases or other harmful contaminants. It is therefore desirable that the used sensor be removed from the device without being grasped or otherwise handled by the user.
One prior art technique involves discharging the used test sensor by sliding the slide latch away from the testing end of the device and simultaneously tipping the testing end of the device downwardly. This requires an awkward manipulation of the device that may be particularly difficult for users, particularly elderly users suffering from diabetes, which lack dexterity in their wrist, hand or fingers. As a result, many users may be tempted to grab the end of the used sensor to remove it from the device.
Another prior technique discloses a button that is depressed to release a previously used test sensor from the sensor-dispensing instrument. However, the release mechanism disclosed in such a prior technique relies primarily on the user tipping the end of the sensor-dispensing instrument down so that gravity will remove the test sensor. It has been found that some test sensors may not properly be ejected by such a prior release mechanism, such as if the test sensor has some contaminant on an exposed surface of the test sensor, such as some adhesive, static electricity may cause the test sensor to remain in the sensor-dispensing instrument, or the light weight of the test sensor makes it unlikely for the test sensor to be removed by gravity from the sensor-dispensing instrument. It is therefore desirable to have an improved sensor-dispensing instrument that utilizes an improved method of discharging used sensors.